Certain types of azole-based compounds are useful as an antifungal agent, and have been used along with antifungal agents based on polyenes, fluoropyrimidine, and candin to treat fungal infections. The azole-based antifungal agents inhibit lanosterol 14α-demethylase and suppress the synthesis of ergosterol, and are therefore believed to bring about impairment of cellular membrane function in fungi. Examples of the known azole-based antifungal agents may include miconazole, ketoconazole, itraconazole, fluconazole, voriconazole, posaconazole, ravuconazole (see Non-Patent Document 1, for example), and the like, and these drugs can be used not only topically, but also by systemic administration (orally or by injection). Therefore, these can be used to treat and prevent invasive aspergillosis, pulmonary candidiasis, fungal meningitis, and other such deep mycoses.
It is known that some of these azole-based antifungal agents are not absorbed in the intestinal tract when taken orally, and therefore do not exhibit their effect. In view of this, there have been attempts at improving absorption by making the compound into an ester (see Patent Documents 1 and 2, for example), or adding a side chain (see Patent Documents 3, 4, and 5, for example).
Patent Document 1: Published Japanese Translation No. 2003-520235 of PCT International Publication
Patent Document 2: Published Japanese Translation No. H10-512599 of PCT International Publication
Patent Document 3: Japanese Patent Application Laid-open No. H11-228548
Patent Document 4: Japanese Patent Application Laid-open No. 2000-169372
Patent Document 5: U.S. Pat. No. 6,812,238
Non-Patent Document 1: Jpn. J. Med. Mycol., 45 (2), 2004